This invention relates to improvements in rivets or fastener devices and, more particularly, to blind setting rivets or fastener devices provided with a drill bit, for the self-drilling thereof through walls or panels which are to be secured together by the rivets or fastener devices.
Rivets or blind fastener devices are well known in the art for securing walls or panels together, the most commonly used being known as "pop-rivets". Other developed blind fasteners are well known as "molly-bolts". Both the "pop-rivet" and the "molly-bolt" require a pre-drilled hole through the walls or panels that are to be joined. Other types of rivets or blind fastener devices which require a pre-drilled hole are discussed in U.S. Pat. Nos. 2,385,886, 3,643,544 and 4,388,031. Each of these patents shows a shank having an enlarged head which is passed through the pre-drilled hole, and then pulled back in such a manner that the enlarged head deforms or spreads out a portion of a sleeve member disposed around the shank, so that the enlarged head is prevented from being pulled back out through the pre-drilled hole. It is noted, that the shank can be provided with external threads thereon to be threaded into the internal threads of the sleeve member so that rotation of the shank will cause the shank to be drawn out from the pre-drilled hole, and thus deform the sleeve member or an associated sleeve, as shown in the above-mentioned U.S. Pat. Nos. 3,643,544 and 4,388,031.
Self-drilling blind rivets or fastening devices are also well known in the art, whereby a drilling bit is provided on the forward end of the shank for drilling the required hole through the walls or panels. Such self-drilling blind rivets are disclosed in U.S. Pat. Nos. 3,750,518, 3,935,786 and 4,629,380, which show similar structure except that the drill tip in U.S. Pat. No. 4,629,380 is detachable during the rivet setting. U.S. Pat. No. 3,403,593 also discloses a self-drilling blind rivet in which the shank is threadedly engaged in the sleeve member. U.S. Pat. Nos. 3,412,594 and 4,085,337 each discloses an installation tool for rotational installation and upsetting of a self-drilling blind rivet.
It is noted, that each of the self-drilling blind rivets disclosed in the above-mentioned patents must have the rear end of the shank secured in and gripped by the jaws of a chuck or the like of an electric drill or the like in order to rotate same so that the drill bit at the opposite forward end of the shank can be drilled through the walls or panels. Accordingly, the chuck jaws must be opened to remove the shank after each rivet setting, and then closed upon the next rivet shank for the installation thereof, this procedure being performed over and over again until all the rivets are installed.